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Artifact 0fac71038875693a937e506bceb492c5f136dd7b1249fbd4ae70b4e8da14f9df:


     1  /*
     2  ** 2003 January 11
     3  **
     4  ** The author disclaims copyright to this source code.  In place of
     5  ** a legal notice, here is a blessing:
     6  **
     7  **    May you do good and not evil.
     8  **    May you find forgiveness for yourself and forgive others.
     9  **    May you share freely, never taking more than you give.
    10  **
    11  *************************************************************************
    12  ** This file contains code used to implement the sqlite3_set_authorizer()
    13  ** API.  This facility is an optional feature of the library.  Embedded
    14  ** systems that do not need this facility may omit it by recompiling
    15  ** the library with -DSQLITE_OMIT_AUTHORIZATION=1
    16  */
    17  #include "sqliteInt.h"
    18  
    19  /*
    20  ** All of the code in this file may be omitted by defining a single
    21  ** macro.
    22  */
    23  #ifndef SQLITE_OMIT_AUTHORIZATION
    24  
    25  /*
    26  ** Set or clear the access authorization function.
    27  **
    28  ** The access authorization function is be called during the compilation
    29  ** phase to verify that the user has read and/or write access permission on
    30  ** various fields of the database.  The first argument to the auth function
    31  ** is a copy of the 3rd argument to this routine.  The second argument
    32  ** to the auth function is one of these constants:
    33  **
    34  **       SQLITE_CREATE_INDEX
    35  **       SQLITE_CREATE_TABLE
    36  **       SQLITE_CREATE_TEMP_INDEX
    37  **       SQLITE_CREATE_TEMP_TABLE
    38  **       SQLITE_CREATE_TEMP_TRIGGER
    39  **       SQLITE_CREATE_TEMP_VIEW
    40  **       SQLITE_CREATE_TRIGGER
    41  **       SQLITE_CREATE_VIEW
    42  **       SQLITE_DELETE
    43  **       SQLITE_DROP_INDEX
    44  **       SQLITE_DROP_TABLE
    45  **       SQLITE_DROP_TEMP_INDEX
    46  **       SQLITE_DROP_TEMP_TABLE
    47  **       SQLITE_DROP_TEMP_TRIGGER
    48  **       SQLITE_DROP_TEMP_VIEW
    49  **       SQLITE_DROP_TRIGGER
    50  **       SQLITE_DROP_VIEW
    51  **       SQLITE_INSERT
    52  **       SQLITE_PRAGMA
    53  **       SQLITE_READ
    54  **       SQLITE_SELECT
    55  **       SQLITE_TRANSACTION
    56  **       SQLITE_UPDATE
    57  **
    58  ** The third and fourth arguments to the auth function are the name of
    59  ** the table and the column that are being accessed.  The auth function
    60  ** should return either SQLITE_OK, SQLITE_DENY, or SQLITE_IGNORE.  If
    61  ** SQLITE_OK is returned, it means that access is allowed.  SQLITE_DENY
    62  ** means that the SQL statement will never-run - the sqlite3_exec() call
    63  ** will return with an error.  SQLITE_IGNORE means that the SQL statement
    64  ** should run but attempts to read the specified column will return NULL
    65  ** and attempts to write the column will be ignored.
    66  **
    67  ** Setting the auth function to NULL disables this hook.  The default
    68  ** setting of the auth function is NULL.
    69  */
    70  int sqlite3_set_authorizer(
    71    sqlite3 *db,
    72    int (*xAuth)(void*,int,const char*,const char*,const char*,const char*),
    73    void *pArg
    74  ){
    75  #ifdef SQLITE_ENABLE_API_ARMOR
    76    if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
    77  #endif
    78    sqlite3_mutex_enter(db->mutex);
    79    db->xAuth = (sqlite3_xauth)xAuth;
    80    db->pAuthArg = pArg;
81 sqlite3ExpirePreparedStatements(db, 0);
82 sqlite3_mutex_leave(db->mutex); 83 return SQLITE_OK; 84 } 85 86 /* 87 ** Write an error message into pParse->zErrMsg that explains that the 88 ** user-supplied authorization function returned an illegal value. 89 */ 90 static void sqliteAuthBadReturnCode(Parse *pParse){ 91 sqlite3ErrorMsg(pParse, "authorizer malfunction"); 92 pParse->rc = SQLITE_ERROR; 93 } 94 95 /* 96 ** Invoke the authorization callback for permission to read column zCol from 97 ** table zTab in database zDb. This function assumes that an authorization 98 ** callback has been registered (i.e. that sqlite3.xAuth is not NULL). 99 ** 100 ** If SQLITE_IGNORE is returned and pExpr is not NULL, then pExpr is changed 101 ** to an SQL NULL expression. Otherwise, if pExpr is NULL, then SQLITE_IGNORE 102 ** is treated as SQLITE_DENY. In this case an error is left in pParse. 103 */ 104 int sqlite3AuthReadCol( 105 Parse *pParse, /* The parser context */ 106 const char *zTab, /* Table name */ 107 const char *zCol, /* Column name */ 108 int iDb /* Index of containing database. */ 109 ){ 110 sqlite3 *db = pParse->db; /* Database handle */ 111 char *zDb = db->aDb[iDb].zDbSName; /* Schema name of attached database */ 112 int rc; /* Auth callback return code */ 113 114 if( db->init.busy ) return SQLITE_OK; 115 rc = db->xAuth(db->pAuthArg, SQLITE_READ, zTab,zCol,zDb,pParse->zAuthContext 116 #ifdef SQLITE_USER_AUTHENTICATION 117 ,db->auth.zAuthUser 118 #endif 119 ); 120 if( rc==SQLITE_DENY ){ 121 char *z = sqlite3_mprintf("%s.%s", zTab, zCol); 122 if( db->nDb>2 || iDb!=0 ) z = sqlite3_mprintf("%s.%z", zDb, z); 123 sqlite3ErrorMsg(pParse, "access to %z is prohibited", z); 124 pParse->rc = SQLITE_AUTH; 125 }else if( rc!=SQLITE_IGNORE && rc!=SQLITE_OK ){ 126 sqliteAuthBadReturnCode(pParse); 127 } 128 return rc; 129 } 130 131 /* 132 ** The pExpr should be a TK_COLUMN expression. The table referred to 133 ** is in pTabList or else it is the NEW or OLD table of a trigger. 134 ** Check to see if it is OK to read this particular column. 135 ** 136 ** If the auth function returns SQLITE_IGNORE, change the TK_COLUMN 137 ** instruction into a TK_NULL. If the auth function returns SQLITE_DENY, 138 ** then generate an error. 139 */ 140 void sqlite3AuthRead( 141 Parse *pParse, /* The parser context */ 142 Expr *pExpr, /* The expression to check authorization on */ 143 Schema *pSchema, /* The schema of the expression */ 144 SrcList *pTabList /* All table that pExpr might refer to */ 145 ){ 146 sqlite3 *db = pParse->db; 147 Table *pTab = 0; /* The table being read */ 148 const char *zCol; /* Name of the column of the table */ 149 int iSrc; /* Index in pTabList->a[] of table being read */ 150 int iDb; /* The index of the database the expression refers to */ 151 int iCol; /* Index of column in table */ 152 153 assert( pExpr->op==TK_COLUMN || pExpr->op==TK_TRIGGER ); 154 assert( !IN_RENAME_OBJECT || db->xAuth==0 ); 155 if( db->xAuth==0 ) return; 156 iDb = sqlite3SchemaToIndex(pParse->db, pSchema); 157 if( iDb<0 ){ 158 /* An attempt to read a column out of a subquery or other 159 ** temporary table. */ 160 return; 161 } 162 163 if( pExpr->op==TK_TRIGGER ){ 164 pTab = pParse->pTriggerTab; 165 }else{ 166 assert( pTabList ); 167 for(iSrc=0; ALWAYS(iSrc<pTabList->nSrc); iSrc++){ 168 if( pExpr->iTable==pTabList->a[iSrc].iCursor ){ 169 pTab = pTabList->a[iSrc].pTab; 170 break; 171 } 172 } 173 } 174 iCol = pExpr->iColumn; 175 if( NEVER(pTab==0) ) return; 176 177 if( iCol>=0 ){ 178 assert( iCol<pTab->nCol ); 179 zCol = pTab->aCol[iCol].zName; 180 }else if( pTab->iPKey>=0 ){ 181 assert( pTab->iPKey<pTab->nCol ); 182 zCol = pTab->aCol[pTab->iPKey].zName; 183 }else{ 184 zCol = "ROWID"; 185 } 186 assert( iDb>=0 && iDb<db->nDb ); 187 if( SQLITE_IGNORE==sqlite3AuthReadCol(pParse, pTab->zName, zCol, iDb) ){ 188 pExpr->op = TK_NULL; 189 } 190 } 191 192 /* 193 ** Do an authorization check using the code and arguments given. Return 194 ** either SQLITE_OK (zero) or SQLITE_IGNORE or SQLITE_DENY. If SQLITE_DENY 195 ** is returned, then the error count and error message in pParse are 196 ** modified appropriately. 197 */ 198 int sqlite3AuthCheck( 199 Parse *pParse, 200 int code, 201 const char *zArg1, 202 const char *zArg2, 203 const char *zArg3 204 ){ 205 sqlite3 *db = pParse->db; 206 int rc; 207 208 /* Don't do any authorization checks if the database is initialising 209 ** or if the parser is being invoked from within sqlite3_declare_vtab. 210 */ 211 assert( !IN_RENAME_OBJECT || db->xAuth==0 ); 212 if( db->init.busy || IN_SPECIAL_PARSE ){ 213 return SQLITE_OK; 214 } 215 216 if( db->xAuth==0 ){ 217 return SQLITE_OK; 218 } 219 220 /* EVIDENCE-OF: R-43249-19882 The third through sixth parameters to the 221 ** callback are either NULL pointers or zero-terminated strings that 222 ** contain additional details about the action to be authorized. 223 ** 224 ** The following testcase() macros show that any of the 3rd through 6th 225 ** parameters can be either NULL or a string. */ 226 testcase( zArg1==0 ); 227 testcase( zArg2==0 ); 228 testcase( zArg3==0 ); 229 testcase( pParse->zAuthContext==0 ); 230 231 rc = db->xAuth(db->pAuthArg, code, zArg1, zArg2, zArg3, pParse->zAuthContext 232 #ifdef SQLITE_USER_AUTHENTICATION 233 ,db->auth.zAuthUser 234 #endif 235 ); 236 if( rc==SQLITE_DENY ){ 237 sqlite3ErrorMsg(pParse, "not authorized"); 238 pParse->rc = SQLITE_AUTH; 239 }else if( rc!=SQLITE_OK && rc!=SQLITE_IGNORE ){ 240 rc = SQLITE_DENY; 241 sqliteAuthBadReturnCode(pParse); 242 } 243 return rc; 244 } 245 246 /* 247 ** Push an authorization context. After this routine is called, the 248 ** zArg3 argument to authorization callbacks will be zContext until 249 ** popped. Or if pParse==0, this routine is a no-op. 250 */ 251 void sqlite3AuthContextPush( 252 Parse *pParse, 253 AuthContext *pContext, 254 const char *zContext 255 ){ 256 assert( pParse ); 257 pContext->pParse = pParse; 258 pContext->zAuthContext = pParse->zAuthContext; 259 pParse->zAuthContext = zContext; 260 } 261 262 /* 263 ** Pop an authorization context that was previously pushed 264 ** by sqlite3AuthContextPush 265 */ 266 void sqlite3AuthContextPop(AuthContext *pContext){ 267 if( pContext->pParse ){ 268 pContext->pParse->zAuthContext = pContext->zAuthContext; 269 pContext->pParse = 0; 270 } 271 } 272 273 #endif /* SQLITE_OMIT_AUTHORIZATION */